1, 3-disubstituted-2-streptomycyl-tetrahydroimidazole, acid addition salts thereof, and therapeutic compositions containing same



United States Patent 1,3-DISUBSTITUTED 2 STREPTOMYCYL-TETRA-HYDROllVIIDAZOLE, ACID ADDITION SALTS THEREOF, AND THERAPEUTICCOMPOSITIONS CONTAINING SAD IE Lee 'C. Cheney, Fayetteville, N. Y.,assignor to Bristol Laboratories Inc., Syracuse, N. Y., a corporation ofNew York No Drawing. Application May 26, 1953, Serial No. 357,620

14 Claims. (Cl. 167-63 This invention relates to a new class of organicchemicals useful in therapeutics and in the manufacture of streptomycinsand, more particularly, to new1,3-substituted-2-streptomycyl-tetrahydroimidazoles and their non-toxicsalts.

Throughout this specification and claims, the names streptomycy andhydroxystreptomycyl are used to represent the radicals attached to thealdehyde group in the widely-known antibiotics streptomycin andhydroxystreptomycin. Thus, the antibiotic streptomycin is represented bythe formula StreptomycylCHO or as Strep.-CHO (see U. S. Patent#2,607,770) rather than by the customary formula. An ordinary salt, suchas the sulfate, is represented as StreptomycylCHO l /2H2SO4 or as 2StreptomycylCHO-3H2SO4.

Up to the present time, there have not been available any active,non-toxic salts or forms or derivatives of streptomycin which arerelatively insoluble in water. In chemical production, this means thatelaborate processes, such as those using ion-exchange columns, arerequired to concentrate a solution of crude streptomycin. Finalcrystallization is 'a complex and expensive process using large amountsof organic solvents and generally also requiring formation of acalcium-chloride double salt before a satisfactory crystalline sulfatecan be prepared. Illustrative processes are given by U. S. Patents#2,446,- 102, 2,541,420, and 2,578,840. Expensive toxic dyes are used byRegna; see U. S. Patents #2,555,762, 2,555,763, 2,560,889, 2,560,890,2,555,761, 2,555,760.

A further disadvantage of known salts and derivatives of streptomycinand the free base is their instability under alkaline conditions, whichirreversibly decompose and inactivate the streptomycin, forming thegammapyrone, maltol.

In therapeutic use, present water-soluble salts and derivatives ofstreptomycin and the free base are rapidly absorbed when administered byinjection, e. g. intramuscularly, and do not give protracted bloodlevels. They are also absorbed very poorly upon oral administration. Inthe treatment of tuberculosis, prolonged high concentrations ofstreptomycin are not necessary and in addition increase thepossibilities of neurotoxic reaction (Antibiotic Therapy, Welch andLewis, Arundel Press, Washington, D. C., 1951, page 104). A repositorypreparation giving prolonged but not too high blood levels is thereforedesired to overcome these opjections and to spare the patient andphysician the inconvenience and expense of numerous injections.

It is an object of the present invention to provide a new series ofderivatives of streptomycin and hydroxystreptomycin and their acidaddition salts, which are non-toxic, therapeutically effective,relatively insoluble in water,

"ice

stable in aqueous alkali and easily regenerated by aqueous acid to theoriginal soluble, active streptomycin.

It is a further object of the present invention to provide improvedprocesses for the isolation and purification, as from inorganic andash-forming impurities, of streptomyci-n from crude, aqueous solution.

It is a further object of the present invention to provide a new seriesof derivatives of streptomycin land 11?- droxystreptomy'cin and theirnontoxic acid addition salts which upon parenteral administration insuitable media provide prolonged blood levels and prolonged therapeuticaction. I

It is an additional object of the present invention to provide a newseries of derivatives of streptomycin and hydroxy-streptomycin and theirnon-toxic acid addition salts which are systemically absorbed andeffective upon oral or buccal, e. g. sublingual, administration.

The objects of this invention have been achieved and there is nowdiscovered, according to the present invention, the new series ofcompounds selected from the group consisting of compounds having theformula (a) H H Rat 1 1-11,

0 S treptmuycyl wherein R1 and R2 represent radicals selected from thegroup consisting of alkyl, cyclopentyl, cyclopentyl-lower alkyl,cyclohexyl cyclohexyl-lower alkyl, lower alkylcyclohexyl-lower alkyl,lower alkoxy-cyclohexyl-lower alkyl, lower alkyl-cyclohexyl, loweralkoxy-cyclohexyl, dehydroabietyl, pyridyl, lower alkyl pyridyl,thiophenelower alkyl, lower alkyl-thiophene-lower alkyl, furanloweralkyl, lower alkyl-furan-lower alkyl, quinolyl-lower alkyl, naphthyl,benzhydryl, piperonyl, thiazolyl, phenyl, lower alkyl-phenyl-loweralkyl, phenyl-lower alkyl, halophenyl-lower alkyl, nitrophenyl-loweralkyl, hydroxyphenyl-lower alkyl, HzN phenyl-lower alkyl, loweralkoxy-phenyl-lower alkyl, alko-Xy-hydroxy-phenyl-lower alkyl, anddi-lower alkyl-monohydroxy-phenyl-lower alkyl; R; and R4 are membersselected from the group consisting of hydrogen and methyl; and (b) acidaddition salts thereof.

The products of the present invention are useful, nontoxic therapeuticagents in diseases of man and animals caused by streptomycin-sensitivetuberculosis bacteria and gram-negative bacteria and are useful asgrowth-stimulating supplements for animals and poultry, as in feeds, andfor use to stimulate the growth of plants, such as radishes, oats andgrass.

Further, as illustrated in detail below, the products of the presentinvention are of particular value in the commercial production ofstreptomycin because, by virtue of their very low solubility in waterand other solvents, they provide improved means for isolation andpurification of streptomycin from impurities, e. g. ash-formingimpurities, streptomycin B.

The products of the present invention are further useful for theirability to provide prolonged, therapeutic bloodlevels upon parenteralinjection in suitable media in comparison with the non-toxicstreptomycin salts of the prior art.

The products of the present invention are prepared by the reaction ofhydroxystreptomycin free base, treptomycin free base or water-solubleacid addition salts thereof, and I prefer streptomycin sulfate, with anequimolar quantity, or more, of an N,N'-substituted-aJS-diaminoalkane,

where there are two to four carbon atoms in the alkane carbon chain. Twoexamples are N,N'-dibenzylethylene- "a I (J 'diamine and.N-p-methylbenzyl-N-beniyl- 1,2-diaminopropane. I prefer to conduct thereaction in water but can also use a mixture of waterand awater-miscible organic solvent such as methanol or acetone when desired,e. g. to solubilize the amine. The reaction takes place at roomtemperature over a period varying from several hours to several days butcan be accelerated by heating, e. g. to 50 C. for twenty minutes. Themixture needs to be maintained at a pH of about 7.0 or higher, sinceacid conditions reverse the reaction and regenerate the startingreagents. The product precipitates as a solid or as an oil whichsoldifies ion seeding. The product may be purified of unreactedstreptomycin reagent, i. e. sulfate, by

slurrying with water.

j Brief heating in aqueous acid regenerates the starting materials andoften precipitates the diamine salt, e.g. N,N'-dibenzylethylenediaminehydrochloride. The purified streptomycin can be recovered in the usualways, as by lyophilization or by crystallization of the sulfate by theaddition of alcohol.

This invention also includes all acid addition salts forp'rocessing'purposeswand all nontoxic acid addition salts fortherapeutic purposes, organic and inorganic examples of which includehydrochloric, sulfuric, sulfamic, tartaric, hydrobromic; hydriodic,glycolic, citric, maleic, phosp'horic, succinic, acetic, benzoic,cinnarnic, mandelic, malic, ascorbic, and the like. I prefer thesulfate.

When the imidazoles of the present invention are used for therapneticpurposes, they maybe used in water with a suspending agent such assodium carboxymethylcellulose, Spans, Tweens, lecithin or pectin or ininjectable oils, e. g. peanut oil gelled with aluminum monostearate inamanner analogous to the art pertaining to insoluble salts of penicillin(see U. S. Patent 2,507,193). If desired, suspending or dispersingagents may be added to increase pharmaceutical elegance. As a suspendingor dispersing agent, sodium carboxymethylcellulose has been found highlysatisfactory but carboxymethylcellulose, methylcellulose, polyvinylalcohol, polyvinylpyrrolidone, gum'tragacanth, gelatin, pectin, sodiumalginates, dextran, gum Karaya, and the like, are also useful. Theamount of suspending agent will vary to a certain extent, but usuallyfrom about 0.2 to 5.0 percent, preferably from 0.5 to 2.5 percent, isemployed and variations within these ranges maybe made by anyexperienced'chemist or pharmacist with regard to the intended use of thecomposition. Thus the concentration of polyvinylpyrrolidone may varyfrom 0.1% to 25%, with about 10% preferred. The concentration of dextranmay vary from 0.1% to 20%, with about 10% preferred. The concentrationof pectin may vary from 0.1% to 0.5%, with about 0.2% preferred. Theconcentration of gum tragacanth may vary. from 0.5% to 2% with about 1%preferred; 5% sodium chloride may be added thereto.

It is to be understood that the words suspending agent and dispersingagent are used interchangeably to describe the additives such as sodiumcarboxymethylcellulose, lecithin, Spans and Tweens which improve thepharmaceutical elegance of these preparations, as by increasing ease ofinjection and ease of resuspension upon settling. Other suspending anddispersing agents include lecithin, Falba, cholesterol, Span 20, Span40, Span 60, Span 80, the Tweens, Amerchols, sodium alginate, potassiumalginate, ammonium alginate, calcium alginate, alginic. acid, propyleneglycol alginate, polyoxyalkylene derivatives of sorbitol fatty acidesters, urea and sodium p-aminobenzoate.

The composition is not limited to the exact ingredients previouslydescribed and .to the exclusion of. all others, since various otheringredients, while not necessary, may be added, if desired. Forinstance, a small amount of preservative,.such as Phenol .U. S. P.,Cresol U. S. P., Methyl Paraben (methyl ester of p-hydroxybenzoic acid),Ethyl .P araben (ethyl ester of p-hydroxybenzoic acid), Butyl Paraben(butyl ester of p-hydroxybenzoic acid) or Propyl Paraben (propyl esterof p-hydroxybenzoic acid). may be employed. Other ingredients whichimprove blood levels, handling properties and stability may be added.Examples of such ingredients are lecithin, Falba, cholesterol, Span 20,Span 40, Span 60, Span 80, Tween 20, Tween 40, Tween 60, Tween 80, Tween85, Amerchols, urea, and sodium para-'amino-benzoate. The Spans arehexitol anhydride (hexitans and hexides derived from sorbitol) partialesters of common long-chain fatty acids (e. g. lauric, palmitic,stearic, oleic) and the Tweens are polyoXyalkylene derivatives of theSpans. On 0ccasion it is advantageous to actually coat the particles ofthe drug, at least in part, W'ithone of these agents, e. g. lecithin.

The diamine reagents of this invention are prepared by the usualsynthetic methods. -Thns by the reaction of ethylene dichloride with anappropriately substituted amine, substituted ethylene diamines areformed. Alternatively, ethylene diamine or its acid addition salts arereacted with formaldehyde and a suitably substituted compound containingan active hydrogen atom, such as aldehydes, ketones, thiophene, organicacids and the like, whereby N,N'-disubstituted ethylene diamines areobtained. In another'method for the preparation of substituted ethylenediamines, a suitably substituted aldehyde or ketone is condensed withethylene diamine to form the correspondingly substituted diimine. Thediimine is hydrogenated by the usual methods, such as catalyticreduction and the like, to give the desired substituted ethylenediamine. Acid addition salts of the substituted ethylene diamines can beprepared by the methods of the art, as, for example, by inter-reactionof equivalent amounts of the substituted diamine base and a selectedacid in inert solvent solution, followed by removal of the solvent. a pj Thus 1,2-bis-(phenylethylamino)ethane is prepared by mixing a solutionof 54 g. (0.5' mole) of 1,2-dibromoethane in 250 cc. of ethanol and 242g. (2 moles) of 2- phenylethylamine. The mixture is boiled for about anhour, made alkaline with potassium hydroxide and boiled for a further10-minute period. The precipitated potassium bromide is removed, thealcohol is evaporated 01f and the residue, comprising1,2-bis-(phenylethy1amino)- ethane, isfractionally distilled underpressure. 1,2-bis- (phenylethy1amino)ethane boils at about 240 C. at thepressure of 15 mm. of mercury.

Thus, in a 500 ml. three-necked flask, fitted with stirrer, condenserand thermometer, are mixed 42 g. (0.5' mole) of thiophene, 33 g. (0.25mole) ethylenediamine dihydrochloride and '43 ml. of 36% aqueousformaldehyde. The mixture is stirred and heated to gradually raisethe'temperatur'e. At 60 C. a vigorous reaction begins, heatingis stoppedand an ice-bath is applied to the flask. The internal temperature risesto about 73 C. and the reaction mixture solidifies. 200 ml. of 50%aqueous alcohol is added and stirred and the mixture is heated anadditional '90 minutes. After cooling, the reaction product is filteredand washed with water. The white product is amorphous and is dissolved,in 250 ml. hot water, cooled and made alkaline with 40% sodiumhydroxide. The free base which separates is not very soluble in etherand is taken up in benzene, dried over sodium hydroxide and is obtainedas a colorless, viscous oil on removing benzene in vacuo. The oil isconverted to diacetate by .dissolving in 200 ml. ethyl acetate andadding 12 ml. glacial acetic acid. The precipitated N,N'-bis(2-thenyl)-ethyl- .enediamine diacetate is collected by filtration, washed withethyl acetate and found to melt at about 84 C.

In essentially the same manner as above, one may. also react an alkylenediamine such as ethylenediamine and an acid; as, for example,hydrochloric, sulfuric or formic acid, to form the di-acid salt togetherwith half amol. of formaldehyde, half a mol. of the following compoundsmay be reacted therewith to form the corresponding symmetricaldi-substituted alkylene diamines: cyclohexanone,

2,3- and 4-methyI-cyclohexanone, 4-methoxy-cyclohexanone,cyclopentanone, Z-methyl-thiophene, isoquinoline, B-methyl-isoquinolineand quinaldine.

Mixed N,N'-mono-substituted-ethylene diamines may be prepared in theways known to the art. Thus, to prepareN-benzyl-N-alpha-ethylbenzyl-ethylenediamine, dimethyl benzylaminoacetal(49 g., 0.25 mol.) and l-phenyl-propylamine (34 g., 0.25 mol.) are mixedin a 500 ml. flask fitted with a reflux condenser with a drying tube.Formic acid (75 1111., 98100%) is added all at once. A vigorous reactionensues with darkening and evolution of heat and of carbon dioxide. Whenthe initial vigorous reaction has subsided, the mixture is heated toreflux for two hours and excess formic acid is then removed bydistillation under reduced pressure to leave a tarry residue to which isadded 150 ml. of 6N HCl. After heating for reflux for one hour, coolingin an ice-bath and making alkaline by the addition of 40% aqueous sodiumhydroxide, the supernatant layer is separated, diluted with 400 ml.ether and filtered to remove tar. The filtrate is dried over sodiumhydroxide and treated with methanolic hydrochloric acid to precipitateN-benzyl-N-alpha-ethylbenzylethylenediamine dihydrochloride, which meltsat about 305 C. after recrystallization from aqueous methanol.

Numerous other N,N'-'bis-(mono-substituted) ethylenediamines may beprepared according to U. S. Patent of N,N'-dibenzylethylenediamine in 25ml. of methanol. Addition of ml. of methanol gave a clear solution.Heating on the steam bath at 4550 C. for ten minutes causedprecipitation of 1,3-dibenzyl-2-streptomycyltetrahydroimidazole sulfateas an oil which crystallized rapidly to a white solid. It was chilled,filtered and air-dried; weight8.4 g.

The product was slurred for a few minutes with ml. of water to insureremoval of all streptomycin sulfate, collected by filtration andair-dried. Weight7.2 g.; M. P.243 247 C. (decomposition, with previousbrowning); solubility-4980 u./ml. or about mgms./ml.; potency-512 u./mg.(83% of theory).

Analysis for C37H57N9O1i-lHzSO4-2HzO: Calculated: C, 47.3; H, 6.77; N,13.45; S, 3.42. Found: C, 47.4; H, 6.42; N, 12.3; S, 3.4.

A 1.5 g. sample of the imidazole was suspended in 25 ml. of 6N HCl andheated for three hours at 100 C. The mixture was filtered and the solidproduct recrystallized from water to give 05 g. ofN,N'-dibenzylethylenediamine dihydrochloride. M. P.-305306 C. (d). Anauthentic sample gave M. P. 305 307 C. (d). The filtrate containedactive, regenerated streptomycin in solution.

EXAMPLE 2 #2,627,491. Formation of N-cyclohexyl-N'-ethyl-ethyl- Theprocedure of Example 1 was repeated with certain enediamine is taught bythis patent by reaction of acetalde- VaflatlOIlS and the following,tabulated lts.

Experiment No. Conditions and Results Run 1 Run 2 Run 3 Moles ofStreptomycin Sulfate 0 005 0,01, Potency of Streptomycin Sulfate 769u./mgm Moles of A min 0 0.0225. Grams of Amine 5 4 Mls. Hz 5 Mls. MeOH-70.

pH Yield (grams) 3.6 5.2 7.2. M. P 245-255 C. (d.) 249-252 C. (d.)243-247" C. (d.). Potency (bio-assay) 630 \L/ gm 500 uJmgm 512 u./mgmSolubility in water of Product 3 2092 u./rnl 4560 u./ml. Reaction TimeRoom temp. for a Room temp. for 45-50 C, fo 10 few hours. 3 days.minutes; Room temp. 24 hours.

1 Product; slurried with 50 ml. water to remove unreacted streptomycinsulfate, collected by filtration, air-dried and then Weighed andassayed.

2 The potency of the product was determined on suspensions by bio-assay(subtilis and colt) due to its insolubility in water, methanol, butanol,ketones, acetonitrile, nitromethane, chloroform, dimethyltormamide andamyl acetate and acetone. The suspensions contained 10 mgms. oifinelyground product per ml. water.

3 The solubility of the product was determined by shaking at least 0.1g. of finely ground material in 10 ml. water for hours, filtering thesolution which contains much undissolved product and assaying thefiltrate (subtilis and colt).

hyde with N cyclohexyl-ethylenediamine followed by catalytichydrogenation; N-benzyl-N-vanilly1ethylenediamine is prepared byreaction of N-benzyl-ethylenediamine with vanill'm followed by reductionwith formic acid. In the same patent are disclosed numerousN-monosubstituted-ethylenediamines (e. g. N-heptylethylenediamine) and ageneral process for their preparation by reaction of an aldehyde (e. g.heptaldehyde) with ethylene diamine diformate. These products can inturn be reacted as their diformates with aldehydes to give diamines ofthe formula R1NHCH2CHz-NHR2 where R1 and R2 differ. v

Further understanding of the invention may be obtained by reference tothe following examples which are illustrative only and are not theexclusive embodiment of the invention. I wish it to be understood that Ido not desire to be limited to the exact details shown and described,for obvious modifications will occur to a person skilled in the art.

EXAMPLE 1 1,3 dibenzyl 2 streptomycyltetrahydroimidazole sulfate To asolution of 7.3 g. (0.01 mole) of streptomycin sulfate in 50 ml. ofwater was added 5.4 g. (0.025 mol.)

EXAMPLE 3 1,3 di(B pherzethyl) 2 streptomycyltetrahydroimidazole sulfateA solution of 2.7 g. (0.01 mole) ofN,N'-di(fi-phenethyl)-ethylenediamine in 20 ml. of methanol was added toa solution of 7.3 g. (0.01 mole) of streptomycin sulfate in 50 ml. ofwater. Portionwise addition of 35 ml. of methanol gave a clear solution.After standing for 24 hours at 5 10 C. the precipitated, solid1,3-di(B-phenethyl)-2-streptomycyltetrahydroimidazole sulfate wascollected by suction. It was hygroscopic and was dried in vacuo overP205. Weight-3.0 g. (30%) of glassy solid. M. P.195205 C. (d. browns at160 C.); solubility in water4400 u./rnl.; potency-396 u./mg. (67.5% oftheory).

Analysis for C39Hs1N9O11-1 /2H2SO4: Calculated: C, 47.9; H, 6.6. Found:C, 48.1; H, 6.9.

EXAMPLE 4 1,3 di(dehydr0abietyl) 2 streptomycyltetrahydroim idazolesulfate A solution of 3.0 g. (0.005 mole) ofN,N'-di(dchydroabietyD-ethylenediamine in 30 ml. of methanol and -10 ml.of acetone was added to a solution of 3.6 g. (0.005

' days.

EXAMPLE 2 streptomycyltetrahydroimidazole sulfate 'A solution. of 2.4grams (0.011 moles) of N,N'-dicyclo- 1,3 dicyclohexylhexylethylenediamine dissolved in the minimum amount of methanol isadded to 7.3 g. (0.01 moles) streptomycin sulfate dissolved in 50 ml.water. The minimum amount of ethanol is added to'ensurc completesolution. After heating at 45 50 C. for ten minutes, the reactionmixture is allowed to stand at room temperature for three days Theproduct, l,3-dicyclohexyl-2-streptomycyltetrahydroimidazole sulfate,precipitates either upon cooling or upon the addition of Water and iscollected by filtration or by decantation.

A 1.5 g. sample of this imidazole is heated for three hours at 100 C. inml. of 6N HCl to regenerate the amine hydrochloride and soluble, activestreptomycin.

EXAMPLE 6 2 streptomycyltetrahydroimidazole sulfate A solution of 1.8grams (about 0.01 moles) of N,N'-

1,3 di tert. butyl di-tertEbutylethylcnediamine. dissolved in the amountof ethanol is added to ensure complete solution.

After heating at 45 50 C. for ten minutes, the reaction mixture isallowed to stand at room temperature for three. The product, '1,3-ditert.-butyl-Z-streptomycyltetrahydroimidazole sulfate, precipitateseither upon, cooling or upon the. addition of water and is collected byfiltration or by decantation.

A. 1.5 gram sample of this imidazole is heated for three hours at 100C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 7 1,3 di (1,l,3,3-tetramethyl-n-butyl)-2-strept0myclytetrahydroimidazole sulfate the addition of water and is collected byfiltration or by.

decantation.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 8- 1,3-di-n-heptyl-2-streptomycyltetrahydroimidazole sulfate Asolution of 2.7 grams (about 0.01 moles) of N,N-

di-n-heptyl-ethylenediamine dissolved in the minimum amount of methanolis added to 7.3 g. (0.01 mole) streptomycin sulfate dissolved in 50ml.water. The minimum 1a unt'of ethanol. is added to ensure completesolution.

at 5.0 C. for ten minutes, the reaction EXAMPLE 91,3-di-benzhya'ryl-2-streptomycyltetrahydroimidazole sulfate A solutionof 4.3 grams (0.01 moles) of N,N-dib'enzhydrylethylenediamine dissolvedin the minimum amount of methanol isaddedto 7.3 g.'(0.0l.mole)streptomycin sulfate dissolved in 50 ml. water. The minimum amountofethan'olis-added to ensure complete solution. After heating at 45 50C. for ten minutes, the reaction mixture is allowed to stand at roomtemperature for three days. The product, l,3-di-benzhydryl- 2streptornycyltetrahydroimidazole sulfate, precipitates either uponcooling or upon the addition of water and is collected by filtration orby decantation.

v A 1.5 gram sample of this imidazole is heated for three hours at C. in25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE l0 1,3-diphenyl-2-strept0mycyltetrahydroimidazole sulfatemethanol is added to 7.3 g. (0.01 mole) streptomycin sulfate dissolvedin 50 ml. Water. The minimum amount of ethanol is added to ensurecomplete solution. After heating at 45 50 C. for ten minutes, thereaction mixture is allowed to stand at room temperature for three days.The product, 1,3-diphenyl-2-streptomycyltetrahydroimidazole sulfate,precipitates either upon cooling or upon the addition of water and iscollected by filtration or by decantation.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 11 N,N'-bis-dehydroabietylethylenea'iamine Dehydroabietylamine(190 grams), ethylene bromide (59.3 g.) and potassium carbonate (92 g.)were mixed EXAMPLE 12 N ,N -bis-(t-0ctyl) -ethylenediamine A mixture of650 grams (5.0 moles) of t-octylamine (Rohm and Haas, B. P. 137-142 C.at 760 mm., also called l-amino-1,1,3,3-tetramethyl-n-butane) and 50 ml.of water was heated under refluxwith stirring during the dropwiseaddition of 188 grams (1.0 mole) of ethylene dibromide, and heating wascontinued for an additional 8 hours. While still Warm, the mixture wastreated with 300 grams of 50% sodium hydroxide; the organic layer wasseparated and Washed with dilute alkali and Water. After drying, thematerial was fractionally distilled to yield about 260 grams (about 92%of theoretical) of N,N'-bis-(t-octyl)-ethylenediamine boiling at Chat apressure of 0.5 mm. Hg. P

1 1 EXAMPLE.

A solution of 2.2 grams of N, N-.d icyclohexylethylenediamiue (M. P. ofhydrate about 82. C.; dihydrochloride melts about 315 C.) dissolved inthe amount of methanol is added to 7.3 g. streptomycin sulfate dissolvedin 50 ml. water. The minimum amount of ethanol is added to ensurecomplete solution. After heatingat 45 '50f C. for ten minutes, thereaction mixture is allowed to stand at room temperature for three days.The product, 1, 3-di(cyclohexyl) -2-streptomycyltetrahydroim-idazolesulfate, is recovered as a'nearly white solid byremoving the solvents bydistillation in vacuo.

A 1.5 gram sample of .this imidazole is heated for three hours 'at 100C. in ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

1,3-bis-(4-methyl-2-pentyl) -2-strept0mycyltetrahydr0- imidazole sulfateA solutionof 2.3 grams of N,N-bis- (4-methyl-2- pentyD-ethylenediamine('B. P. about 96 C./1 mm.) dissolved in the minimum amount of methanolis added to 7.3 g. streptomycin sulfate dissolved in 50 ml. water. Theminimum amount of ethanol is added to ensure complete solution. -Afterheating at 4'5 50 C. for ten minutes, :the reaction mixture is allowedto stand at room temperature for three days. The solid product,-l,3-bis- (4-methy'l-2-pentyl) 2 streptomycyl tetrahydroimidlazolesulfate, precipitates upon seeding and'the addition of water and iscollected by filtration and dried.

A- 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml.- of '6N 'HCl to regenerate the amine hydrochlorideand-soluble, active streptomycin.

EXAMPLE 22 1 ,3 -bis-( 3,5 ,5 trihtethylhexyl -2-streptomycyl-tetrahydfoimidazole sulfate A solutionof 3.1 grams ofN,N-his-(3,5,5-t-rimethyl hexyD-ethylenediamine (B. P. about 150T/ 1.2mm.) dissolved in the minimum amount of methanol is added to 7.3g.'streptomycin sulfate dissolved in 50 ml. water. The amount of ethanolis added to ensure complete solution. After heating at 45 -'50 C. for--ten minutes, the reaction mixture is allowed to stand at roomtemperature for three days. The product,V1,3-bis 3,5,'5-trimethylhexyl)-2-streptomycyl-tetrahydroimidazole sulfate, is recovered :as asolid by lyophilization.

A il.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HOlto regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 2'3 1 ,3 -b is p-ch lorobenzyl -2-streptomycyl tetrahydtoimidazole sulfate i hours at 100 C. in 25 .ml. of :6N HCl to regeneratethe.

amine liy drochloride and soluble. active streptomycin. H

--1 2 EXAMPLE 24 1 ,3-bis- 2,4:dich lorobenzyl -2 -streptomycyl-tetralzydroimidaz ole sulfate A solution of 3.8 grams ofN,N-bis-(2,4-dichlorobenzyl)-ethylenediamine (picrate melts about 183C.) dissolved in the minimum amount of methanol is added to 7.3 g.streptomycin sulfate dissolved in 50 ml. water. The minimum amount ofethanol is added to ensure com.- plete solution. After heating at 45 -50C. for ten minutes, the reaction mixture is allowed to stand at roomtemperature for three days. dichlorobenzyl)-2-streptomycyltetrahydroimidazole' sulfate, precipitates upon cooling asa somewhatyellow oil which on standing becomes crystalline. The crystalsareremoved by filtration and dried in vacuo.

A 1.5 gram sample of this imidazole is heated for three hours at C. in25 ml. of 6N HCl to regenerate the amine hydrochloride andlsoluble,active streptomycin.

EXAMPLE 2s 1,3-bis-(p-1zitrobenzyl) -2-streptomycyl-tetrahydroimidazolesulfate A solution of 3.3 grams of N,N'-bis-(p-nitrobenzyl)-ethylenediamine (dihydrochloride melts about 290 C.) dissolved in theminimum amount of methanol is added to 7.3 g. streptomycin sulfatedissolved in 50 ml. water. The minimum amount of ethanol is added toensure complete solution. After heating at 45 50 C. for ten minutes, thereaction mixture is allowed to stand at room temperature for three days.The alcohol is removed by distillation in vacuo below 50 C. and replacedby water; upon cooling the product, 1,3-bis-(p-nitrobenzyl)-2-streptomycyl-tetrahydroim-idazole sulfate, precipitates as a gum whichgradually solidifies upon seeding.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

' EXAMP LEr26 LS-bis-(p-aminbbenzyl)-2 streptomycyl tetrahydroimidazolesulfate A; solution of 2.7 grams of N,N-bis-(p-aminobenzyl)-ethylenediamine (dihydrochloride melts above 300 C.) dissolved in theminimum amount of methanol is added to 7.3 g. streptomycin dissolved in50 ml. Water. The

minimum amount of ethanol is added to ensure complete solution. Afterheating at 45 -50 C. for tenminutes, the reaction mixture is allowed tostand at room temperature for three days. The product,1,3-bis-(p-aminobenzyl)-2 streptomycyl tetrahydroimidazole sulfate,precipitates upon the addition of water and'is filtered oif and dried.

' A 1.5 gram sample of this imidazole is heated for three hours at 100C. in 25 ml. of 6N HCl to regenerate the amine hydrochloride andsoluble, active streptomycin.

EXAMPLE 27 1,3-bis- (p-methoxybenzyl) -2-stfeptomycyl-tetrahydroimidazolesulfate A 1.5 gram sample of this imidazole is heated for threehours at 100 C. in 25 ml. of 6N HCl to regenerate the aminehydrochloride and soluble, active streptomycin.

The product, 1,3-bis-(2,4-,

13 1 EXAMPLE 2s 1 ,3-bis- (Z-thezgyl) -2-strept0myayltetrahydroimiaazole sulfate A solution of 2.5 grams ofN,N"-bis-(2-thenyl) -ethy1- enediamin'e -(diacetate melts about 84 C.)dissolved in the minimum amount of methanol is added to 713 g.streptomycin sulfate dissolved in 50 ml. water. The minimum amount ofethanol is added to ensure complete solution. After heating at 45-50 C.for ten minutes, the reaction mixture is allowed to stand at roomtemperature for three days. After cooling, the crystalline product, 1,-3-bis-(2-thenyl) -2-streptomycylrtetrahydroimidazole sulfate, is filteredoff and dried.

A 1.5 gram sample of this imidazole 'is heated for three hours at 100 C.in 25ml. of 6N 'HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 29 1,3-bis- (Z-methyl-cyclohexylmethyl)-2-strept0mycyltetrahydroimidazole sulfate A solution of 2.8 grams ofN,N'-bis-(Z-methyl-cyclohexylmethyl)-ethylenediamine dissolved in theminimum amount of methanol is added to 7.3 g. streptomycin sulfatedissolved in 50 ml. water. The minimum amount of ethanol is added toensure complete solution. After heating at 45 50 C. for ten minutes, thereaction mixture is allowed to stand at room temperature for three days.Lyophilization of the reaction mixture leaves solid 1,3-bis-Z-methyl-cyclohexylmethyl) -2-streptomycyl tetrahydroimidazole sulfate.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 30 J ,3-bis- (3 -methyl-cyclohe.xylmethyl-2-strept0mycyltetrahydroimidazole sulfate A solution of 2.8 grams ofN,N'-bis-(3-methyl-cyclohexylmethyl)-ethylenediamine dissolved in theminimum amount of methanol is added to 7.3 g. streptomycin sulfatedissolved in 50 ml. water. The minimum amount of ethanol is added toensure complete solution. After heating at 45 --50" C. for ten minutes,the reaction mixture is allowed to stand at room temperature for threedays. The alcohol is removed by distillation in vacuo below 50 C. andreplaced by water; upon cooling the product, 1,3- bis-(B-methyl-cyclohexylmethyl) -2-streptomycyl tetrahydroimidazole sulfate,precipitates as a gum which gradually solidifies upon seeding.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 31 1,3-bis-(4-methyl-cyclohexylmethyl) -2-strept0mycyltetrahydroimidazole sulfate A solution of 2.8 grams ofN,N-bis-(4-methyl-cyclohexylmethyl)-ethyler1ediamine dissolved in theminimum amount of methanol is added to 7.3 g. streptomycin sulfatedissolved in 50 ml. water. The minimum amount of ethanol is added toensure complete solution. After heating at 45 -50 C. for ten minutes,the reaction mixture is allowed to stand at room temperature for threedays. The precipitate of 1,3-bis-(4-methyl-cyclohexylmethyl)-2-streptomycyl-tetrahydroimidazole sulfate which separates upon theaddition of water is collected by filtration and dried.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 m1. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

1.4. EXAMPLE 321,3-bis-(4-methoxy-cyelahexylmethyl)-2-streptomycyltetrahydroimidazolesulfate A solution of 3.1 grams ofN,N-bis-'(4-methoxy-eyclohexylmethyl)-ethylenediamine dissolved in theminimum amount of methanol is added to 7.3 g. streptomycin sulfatedissolved in 50 ml. water. The minimum amount of ethanol is added toensure complete solution. After heating at 45 50' C. for ten minutes,the reaction mixture is allowed to stand at room temperature for threedays. The product, 1,3-bis-(4-methoxy-cyclohexylmethyl)-2-streptomycyl-tetrahydroimidazole sulfate, is recovered as a nearlywhite solid by removing the solvents by distillation in vacuo.

A 1.5 gram sample of this imidazole is heated for three hours at C. in'25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 33 1,3-bis-(3-methoxy-c clohexylmethyl) -2-stre tomcyltetrahydroz'mizla'zol'e sulfate A solution of 2.2 grams ofN,N-bis(3-methoxy cyclohexylmethyl)-ethylenediamine dissolved in theamount of methanol is added to 7.3 g. streptomycin sulfate dissolved in50 ml. water. The minimum amount ethanol is added to ensure completesolution. After heating at 4550 C. for ten minutes, the reaction 'miX-ture is allowed to stand at room temperature for three days. Theproduct,1,3-bis-(3-methoxy-cyclohexylmethyl)-2-streptomycyl-tetrahydroimidazolesulfate, is recovered as a solid by lyophilization.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochion'de and soluble,active streptomycin.

EXAMPLE 34 1,3-bis-2-(Z-methylthenyl)-2-streptomycyltetrah'ydroimidazole sulfate A solution of 2.8 grams ofN,N'-bis-2-(Z-methylthenyl)- ethylenediamine dissolved in the minimumamount of methanol is added to 7.3 g. streptomycin sulfate dissolved in50 ml. Water. The minimum amount of ethanol is added to ensure completesolution. After heating at 45 50 C. for ten minutes, the reactionmixture is allowed to stand for three days at room temperature. Theproduct, 1,3 -bis-2-(2-methy1thenyl) -2-streptomycyltetrahydroimidazolesulfate, precipitates upon cooling as a somewhat yellow oil which onstanding becomes crystalline. The crystals are removed by filtration anddried in vacuo.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 35 1 ,3-bis-2- quinolylethyl) -2-strept0mycyl-ttraltydroimidazole sulfate A solution of 3.7 grams ofN,N-bis-2-(quinolylethyl)- ethylenediamine dissolved in the minimumamount of methanol is added to 7.3 g. streptomycin sulfate dissolved in50 ml. water. The minimum amount of ethanol is added to ensure completesolution. After heating at 45 -50 C. for ten minutes, the reactionmixture is allowed to stand at room temperature for three days. Theproduct, 1,3-bis-2-(quinolylethyl)-2-streptomycyl-tetra f hydroimidazolesulfate, precipitates upon the addition of water and is filtered off anddried.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regriefate' the amine hydrochloride and soluble,active streptomycin.

' 15 EXAMPLE36 I benzyl-ethylenediamine (dihydrochloride melts about 306C.) dissolved in the minimum amount of methanol is added to 7.3 g.streptomycin sulfate dissolved in 50 ml. water. The minimum amount ofethanol is added to ensure complete solution. After heating at 45 -50 C.for ten minutes, the reaction mixture is allowed to stand at roomtemperature for three days. The solid product, 1benzyl-3-alpha-ethylbenzyl-2-streptomycyl tetrahydro imidazole sulfate,precipitates upon seeding and the addition of water and is collected byfiltration and dried.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 37 1,3-bis- (p-methylbenzyl) -2-streptomycyl-tetrahydroimidazolesulfate A solution of 2.7 grams of N,N'-bis-(p-methylbenzyl)-ethylenediamine (diacetate melts about 116 C.) dissolved in the minimumamount of methanol is added to 7.3 g. streptomycin sulfate dissolved in50 ml. water. The minimum amount of ethanol is added to ensure completesolution. After heating at 45 50 C. for ten minutes, the reactionmixture is allowed to stand at room temperature for three days. Uponcooling and the careful addition of water, the solid1,3-bis-(p-methylbenzyl)-2 streptomycyl-tetrahydroimidazole sulfateseparates and is collected by filtration. w

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 38 1 ,3-bis( m-m ethylbenzyl -2 -streptmycyl-tetrahydr0-imidazole sulfate A solution of 2.7 grams of N,N"-bis (m-methylbenzyl)-ethylenediamine dissolved in thefminimum amount of methanol is added to7.3 g. streptomycin. sulfate dissolved in 50 ml. water. The minimumamount of ethanol is added to ensure complete solution. After heating at45 50 C. for ten minutes, the reaction mixture is allowed to stand forthree days at room temperature. After cooling, the crystalline product,1,3-bis(m-methylbenzyl)- Z-streptomycyl-tetrahydroimidazole sulfate, isfiltered off and dried.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 39 1,3-bis(0-methylbenzyl) -2-streptomycyl-tetrahydroimidazolesulfate A solution of 2.7 grams of N,N'-bis(o-methylbenzyl)-ethylenediamine dissolved in the minimum amount of methanol is added to7.3 g. streptomycin sulfate dissolved in 50 ml. water. 'The minimumamount of ethanol is added to ensure complete solution. After heating at45 -50 C. for ten minutes, the reaction mixture is allowed to stand atroom temperature for three days. Lyophilization of the reaction mixtureleaves solid 1,3-bis(omethylbenzyl) 2- streptomycyl tetrahydroimidazolesulfate.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride, and soluble,active streptomycin.

15 EXAMPLE 40 1.31 2 3-(b qny hyl):Z- lommk- 1 tetrahydroirnidagolesulfate A solution of 3.0 grams of N,N'-bis-(beta-phenylethyl)-ethylenediamine (diacetate'melts about 114 C.)

dissolved in the amount of methanol is added to 7.3 g. streptomycinsulfate dissolved in 50 ml. water.

The minimum amount of ethanol is added to ensure com-- plete solution.After heating at -50 C. for ten min utes, the reaction mixture isallowed to stand at room temperature for three days. t-illation in vacuobelow C. and replaced by water;

upon cooling the product, 1,3-bis-(beta-phenylethyl) 2streptomycyl-tetrahydroimidazole sulfate, precipitates as a. gum whichgradually solidifies upon seeding.

A 1.5 gram sample of this imidazole is heated for three hoursat 100 C.in25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 41 1,3-bis-(lauryl)-2-strept0mycyl-tetrahydro- 5 imidazolesulfate sure complete solution. After heating at 45 50 C. for

ten minutes, the reaction mixture is allowed to stand at roomtemperaturefor three days. The precipitate of 1,3-

bis-(lauryl)- 2-,streptomycyltetrahydroimidazole sulfate which separatesupon the addition of Water is collected by filtration and dried. r

1 A15 gram sample of this imidazole is heated for three hours at C. in25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 42 1,3 -'bis a methy lcyclbhexyl) 2'- streptoluycyltetrahydroimidazole sulfate A solution of 2.5 grams of N,N'-bis-(3-mcthylcyclohexyl)-ethylenediamine dissolved in the minimum amount ofmethanol is added to 7.3 g. streptomycin sulfate dissolved in 50 ml.water. The minimum amount of ethanol is added to ensure completesolution. After heating at 45 50 C. for ten minutes, the reactionmixture is allowed to stand at room temperature for three days. Theproduct, 1,3 bis (3 methylcyclohexXD- 2-streptomycyl-tetrahydroimidazolesulfate, is recovered as a nearly white solid by removing the solventsby distillation in vacuo.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regener-. ate the amine hydrochloride andsoluble, active strepto mycin.

EXAMPLE 43 methylcyclohexyl) 2 streptomycyl- 1,3 bis (2tetrahydroimidazole sulfate A 1.5 gram sample of this imidazole isheated for 7 three hours at 100 C. in.2-5.ml. of 6N HCl to regeneratethe amine hydrochloride and soluble, active strepto mycin.

The alcohol is removed by disarcane upon cooling as a somewhat yellowoil which on standing becomes crystalline. The crystals are removed byfiltration and dried in vacuo.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 45 1,3 bz's (3 n'itrophenyl) 2 stre ptomycyl-tetrahydroimidazole sulfate A solution of 3.3 grams ofN,N'-bis-(3-uitrophenyl)- cthylenediamine dissolved in the minimumamount of methanol is added to 7.3 g. streptomycin sulfate dissolved in50 ml. water. The minimum amount of ethanol is added to ensure completesolution. After heating at 45 50 C. for ten minutes, the reactionmixture is .allowed to stand at room temperature for three days. 7 Theproduct, 1,3 bis (3 nitrophenyl) 2 streptomycyltetrahydroimidazolesulfate, precipitates upon the addition of water and is filtered off anddried.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 46 1,3-bz's-2-(6-mthylpyridyl) -2streptomycyltetrahydroimz'dazole sulfate A solution of 2.4 grams ofN',N-bis-2-(6-methylpyridyl)-ethy1enediamine dissolved in the amount ofmethanol is added to 7.3 g. streptomycin sulfatedissolved in 50 ml.water. The minimum amount of ethanol is added to ensure completesolution. After heating at 45 -50 C. for ten minutes, the reactionmixture is allowed to stand at room temperature for three days. Thesolid product,1,3-bis-2-(6-methylpyridyl)-2-streptomycyltetrahydroimidazole sulfate,precipitates upon seeding and the addition of water and is collected byfiltration and dried.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.v

EXAMPLE 47 1,3-bis-2-(5-methylpyridyl)--2streptomycjl-tetrahydraimz'dazole sulfate A solution of 2.4 grams ofN,N'-bis-2-(5-' methylpyr idyl) -ethylenediamine dissolved in the ofmethanol is added to 7.3 g. streptomycin sulfate dissolved in 50 ml.water. The minimum amount of ethanol is added to ensure completesolution. Atter heating at 4550 C. for ten minutes, the reaction mixtureis allowed to stand at room temperature for three days. Upon cooling andthe careful additionjof water, the solid 1,3-bis-2-(5-methylpyridyl)-2-streptomycyl-tetrahydroimid'azole sulfate separatesand is collected by filtration. H K V I v A 1.5 gram sample of thisimidazole is heated for hours at 100 C. in 25 m1. of 6N HCl toregenerate the amine hydrochloride and soluble, activ'e streptomycin.

5 EXAMPLE 48 1,3 =5is-2-(4-fnethylpyridyl -2-streptomycyl-tetrahytlr0-imidazole sulfate A solution of 2.4 grams ofN,N'-bis-2-(4-methylpyridyl)-ethyleuediamine dissolved in the minimumamount of methanol is added to 7.3 streptomycin sulfate dissolved in 50ml. water. The minimum amount of ethanol is added to ensure completesolution. After heating at 4-5 50 C. for ten minutes, the reactionmixture is allowed to stand at room temperature for three days. Aftercooling, the crystalline product, 1,3-bis-2-(4-methylpyridyl)2-streptomycyl-tetrahydroimidazole sulfate, is filtered oil? and dried.

v A 1.5 gram sample of this imidazole is heated for three hou'rsat C. in25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 49 1,3-bis-2-(3-methylpyridyl)-2-streptomycyl-tetrahydroimidazole sulfate A solution of 2.4 grams ofN,N'-bis-2-(3-methylpyr- .idyl') -'ethy1enediamine dissolved in theamount of methanol is added to 7.3 g. streptomycin sulfate 'dissolved in50 ml. water. The minimum amount ofe'thanol is added to ensure completesolution. After heating at 45 50 C. for ten minutes, the reactionmixture is allowed to stand at room temperature for three days.Lyophilization of the reaction miXturesleaves solid 13-. bis 2 (3methylpyridyl) 2 streptomycyl tetrahydroimi'dazole sulfate.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 50 l ,3-bis-2-thiaz0lyl-2-streptomycyl-tetrahydroimidazolesulfate A solution of 2.3 grams of N,Nbis-2-thiazolyl-ethylenediaminedissolved in the minimum amount of methanol is added to 7.3 gramsstreptomycin sulfate dissolved in 50 ml. water. The minimum amount ofethanol is added to ensure complete solution. After heating at 4550 C.for ten minutes, the reaction mixture is allowed tostand at roomtemperature for three days. The alcohol is removed by distillation invacuo below 50 C. and replaced by water; upon cooling the product,1,3-bis- 2 thiazolyl 2 streptomycyl tetrahydroimidazole sulfate,precipitates as a guru which gradually solidifies upon seeding. V

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 51 1 ,3 -bz's-2 (5 -methylfuryl -2 -strep tomycy l-tetrahydroimidazole sulfate A solution of 2.2 grams of N,N'bis-2(5-methylfu1fyl)- ethylenediamine dissolved in the minimum amountof methanol is added to 7.3 g. streptomycin sulfate dissolved in 50 ml.Water. The minimum amount of ethanol is added to ensure completesolution. After heating at 45 -50 C. for ten minutes, the reactionmixture is allowed to stand at room temperature for three days. Theprecipitate of 1,3-bis-2(5-methylfuryl)-2streptomycyl-tetrahydroimidazole sulfate which separates upon theaddition of water is collected by filtration and dried.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 m1. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

in 50 ml. water.

added to ensure complete solution.

9 EXAMPLE 52 1;3-bis-(p-hydroxybenzyl) -2-'streptomycyl-tetrahydroimidazole sulfate A solution of 2.7 grams ofN,N-bis-(p-hydroxybenzyl)-ethylenediarnine (dihydrochloride melts about242 C.) dissolved in the minimum amount of methanol is added to 7.3 gstreptomycin sulfate dissolved in 50 ml. water. The minimum amount ofethanol is added to ensure complete solution. After heating at 45 '50 C.for

EXAMPLE 53 1 ,3-bis-(cyclpentyl) -2 streptomycyl-tetrahydroimidazolesulfate A solution of 2.0 grams'of N,N'-bis-(cyclopentyl)-ethylenediamine dissolved in the minimum amount of methanol is added to7.3 g. streptomycin sulfate dissolved The minimum amount of ethanol isAfter heating at 4550 C. for 'ten minutes, the reaction mixture isallowed, to stand at room temperature for three days. The product,1,3-bis-(cyclopentyl)-2-streptomycy1-tetrahydroimidazole sulfate, isrecovered as a solid by lyophilization.

A 1.5 gram sample of this imidazone is heated for A solution of v 3.7grams of N,N-bis(undecyl)-ethylenediamine dissolved in the minimumamount of meth- '20 7 EXAMPLE '56 1,3-bisvanillyl) -2-st rep tomycyl-tetrgzhydroimidazole H ,sulfate 4 A solution of 3.3 grams ofN,N'-bis-(van illyl)-ethyl- 'enediamine dissolved in the minimum amountof methanol is added to 7.3 g. streptomycin sulfate dissolved in '50 ml.water. The minimum amount of ethanol is added to ensure completesolution. After heating at 45 50- C." for ten'minutes, the reactionmixture is allowed to stand atroorn temperature for three days. Thesolid product, 1,3-bis- (vanillyl) -2-streptomycyl-tetrahydroimida zolesulfate, precipitates upon seeding and .the addition of water and iscollectedby'filtration and dried.

A 1".5 gram sample of this imidazole is heated for three hours at 100 C.in 25 'ml. of 6N HCl to regeiier- V ate the amine hydrochloride and'soluble, active strepto- .35 three hours at 1100" C. in 25 ml. of 6NHCl to regenanol is added to 7.3 g. streptomycin sulfate dissolved in501ml. water. The minimum amount of ethanol is added .to ensure completesolution. After heating at 45 -50 C. for ten minutes, the reactionmixture is allowed to standat room temperature for three days. Theproduct,

. 1,3-bis- (undecyl) -2-streptomycyl-tetrahydroimidazole sulfate,precipitates upon cooling as a somewhat'yellow oil which on standingbecomes crystalline. The crystals are removed by filtration and dried invacuo.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in '25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 1,3-bis- (4-meth oxycycloh exyl)-2-strept0mycyl-tetrahydroimidazole sulfate heating at 45 50 C. for tenminutes, the reaction mixture is allowed to stand at room temperaturefor three days. The product, 1,3-bis-(4-methoxycyclohexyl)-2-streptomycyl-tetrahydroimidazole sulfate, precipitates upon theaddition of Water and is filtered off and dried.

A 1.5 gram sample of this imidazole is heated for three hours at 100? C.in 25 m1. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

mycin. r

' EXAMPLE 57 1-cycloheryl-3-ethyl-2-streptomycyl-tetrahya'roirriidaz olesulfate A solution of 1.7 grams of N-cyclohexyl-N-ethyl-ethylenediaminedissolved in the minimum amount of methanol is added to 7.3 gramsstreptomycin sulfate dissolved in 50 ml. water. The minimum amount ofethanol is added to ensure complete solution. After heating at 45 50 C.for 'ten minutes, the reaction mixture is allowed to stand at roomtemperature for three days. Upon cooling and the careful addition ofwater, the solid 1cycloheXyl-3-ethyl-2-streptornycyl-tetrahydroimidazole sulfateseparates'and is collected by filtration.

-A 1.5 gramsample ofthis imidazole is heated for three hours at C. in 25ml. of 6N HCl to regenerate the amine hydrochloride and soluble, activestreptomycin.

EXAMPLE 5s 1-benzyl-3-vanillyl sulfate A solution of 2.9.grams. ofN-benzyl-Nwanillyl-ethyL enediamine dissolved in the minimum amount ofmethanol is added to 7.3 grams streptomycin sulfate dis- .solved in 50ml. water. The minimum amount of ethanol is added to'ensure completesolution. After heating at 45 50 C. for ten minutes,the reaction mixtureis allowed to stand at room temperature for three days; After cooling,

the crystalline product, l-benzyl-3-vanillyl-2-streptomycyltetrahydroimidazole sulfate, is' filtereded? and dried.

, A 1.5 gram sample of this imidazole is heated for three hours at 100C. in 25 ml. of 6N HCl to regeneratethe amine hydrochloride and soluble,active streptomycin.

EXAMPLE 59 l,3-di-n-butyl-2-streptomycyl-tetrahydroimidazole sulfate 7 Asolution of 1.7 grams of N,N-di-n-butyl-ethylenediaminedissolved in theminimum amount of methanol is A solution of 1.7 grams ofN,N-di-iso-butyl-ethylenediamine dissolved in the minimum amount'ofmethanol is added to 7.3 g. streptomycin sulfate dissolved in 50 ml.water. The minimumamount of ethanol. is added to ensure. completesolution. After heating at 45 -50 C.

2 streptomycyl-tetrahydroimidazole The minimum amount of ethanol isadded to ate /3116 21, for ten minutes the reaction mixture is allowedto stand at room temperature for three day. The alcohol is removed bydistillation in vacuo below 50 C. and replaced by water; upon coolingthe product, 1,3-di-iso-butyl-2- -streptomycyl-tetrahydroimidazolesulfate, precipitates as a gum which gradually solidifies upon seeding.

A 1.5 gram sample of this hnidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 61 1,3-di-sec.-butyl 2 streptomycyl tetrahydroimidazole sulfateAsolution of 1.7 grams of N,N-di-sec. butyl-ethylenediamine dissolved inthe minimum amount of methanol is added to 7.3 g. streptomycin sulfatedissolved in 50 ml. water. The minimum amount of ethanol is added toensure complete solution. After heating at 45 50 C. ten minutes, thereaction mixture is allowed to stand at room temperature for three days.The precipitate of 1,3- di-sec.-butyl 2 streptomycyl-tetrahydroimidazolesulfate which separates upon the addition of Water is collected byfiltration and dried.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 62 1,3 bis- (1 naph thyl) -2-strept0mycyl-tetruhydroimidazolesulfate A solution of 3.1 grams of N,N-bis-(1-naphtl1yl)-ethylenediamine dissolved in the minimum amount of methanol is added to7.3 g. streptomycin sulfate dissolved in 50 ml. water. The minimumamount of ethanol is added to ensure complete solution. After heating at4550 C. for ten minutes, the reaction mixture is allowed to stand atroom temperature for three days. The precipitate ofl,3-bis-(l-naphthyl)-2-streptomycyl-tetrahydroimidazole sulfate isrecovered as a nearly white solid by removing the solvents bydistillation in vacuo.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 63 1,3 bis-(Z-naphthyl) -2-streptomycyl-tetrahydroimia'azolesulfate A solution of 3.1 grams of N,N'-bis-(Z-naphthyD-ethylenediaminedissolved in the minimum amount of methanol is added to 7.3 g.streptomycin sulfate dissolved in 50 ml. water. The minimum amount ofethanol is added, to ensure complete solution. After heating at 4550 C.for ten minutes, the reaction mixture is allowed to stand at roomtemperature for three days. Upon cooling and the careful addition ofwater, the solid 1.3-bis-(2-naphthyl)-2-streptomycyl-tetrahydroimidazole sulfate separams and iscollected by filtration.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 64 1,3-bis- (2-pyrl'dyl) -2-strept0mycyl-tetrahydroimidazolesulfate A solution of 2.1 grams of NJ -bis-(2-pyridyl)-ethylenediaminedissolved in the minimum amount of methanol is added to 7.3 g.streptomycin sulfate dissolved in 50 ml. Water. The minimum amount ofethanol is added to ensure complete solution. After heating at 4550 C.for ten minutes, the reaction mixture is allowed to stand at roomtemperature for three days. The product, 1,3 his(2-pyridyl)-2-streptomycyl-tetrahydroimidazole sulfate, is recovered asa solid by lyophilization.

A 1.5 gram sample of this imidazole is heated for three 22 hours at C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 65 1,3 bisbenz'hydryl) -2-strep tomycyl-tetrahydroifrlidazolesulfate A solution of 3.9 grams of N,N-bis-(benzhydryl) -ethy1-enediamine dissolved in the minimum amount of methanol is added to 7.3g. streptomycin sulfate dissolved in 50 ml. water. The minimum amount ofethanol is added to ensure complete solution. After heating at 45 50 C.for ten minutes, the reaction mixture is allowed to stand at roomtemperature for three days. The product, 1,3-bis-(benzhydryl)-2-streptomycyl-tetrahydroimidazole sulfate,precipitates upon cooling as a somewhat yellow oil which on standingbecomes crystalline. The crystals are removed by filtration and dried invacuo.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

nXAMetn 66 1,3-bis-(3,4-dimethoxybenzyl)-2-.streptomycyl-tetrahydroimidazole sulfate A solution of 3.6 grams ofN,N-bis-(3,4-dimethoxybenzyl) ethylenediamine dissolved in the minimumamount of methanol is added to 7.3 g. streptomycin sulfate dissolved in50 ml. water. The minimum amount of ethanol is added to ensure completesolution. After heating at 45-50 C. for ten minutes, the reactionmixture is allowed to stand at room temperature for three days. Theproduct,1,3-bis-(3,4-dimethoxyhenzyl)-2-streptomycyl-tetrahydroimidazolesulfate, is recovered as a nearly White solid by removing the solventsby distillation in vacuo.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 67 1,3-bis- (amyl) -2-strept0mycyl-tetraltydroimidazole sulfateA solution of 2.0 grams of N,N-bis-(amyl)-ethylenediamine dissolved inthe minimum amount of methanol is added to 7.3 g. streptomycin sulfatedissolved in 50 ml. Water. The minimum amount of ethanol is added toensure complete solution. After heating at 45 5 0 C. for ten minutes,the reaction mixture is allowed to stand at room temperature for threedays. The solid product,1,3-bis-(amyl)-2-streptomycyl-tetrahydromimidazole sulfate, precipitatesupon seeding and the addition of water and is collected by filtrationand dried.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 68 1-benzyl-3-p-methoxybeuzyl-Z-strept0mycyl-teirahydroimidazole sulfate Asolution of 2.7 grams of N-benzyl-N'-p-methoxybenZyl-ethylenediaminedissolved in the minimum amount of methanol is added to 7.3 g.streptomycin sulfate dissolved in 50 ml. water. The minimum amount ofethanol is added to ensure complete solution. After heating at 45 -50 C.for ten minutes, the reaction mixture is allowed to stand at roomtemperature for three days. The product, l-benzyl-3-p-methoXybenzyl2-strcptomycyl-tetrahydroimidazole sulfate, precipitates upon theaddition of water and is filtered off and dried. V

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

l in 50 ml. water.

V H EXAMPLE69 i l-ethyl-3pheuethyl-Z-streptomycyl-tetruhydroimidazolesulfate A solution of 1.9 grams of N-ethyl-N-phenethylethylenediaminedissolved in the minimum amount of methanol is added to 7.3 g.streptomycin sulfate dissolved The minimum amount of ethanol is added toensure complete solution. After heating at 45 50 C. for ten minutes, thereaction mixture is allowed to stand at room temperature for three days.Upon cooling andjthe careful addition of water, the solid 1- ethyl 3-phenethyl-2-streptomycyl-tetrahydroimidazole sulfate separates and iscollected by filtrationf A 1.5 gram sample of this imidazole is heatedfor three hours at 100 C. in 25, ml. of 6N HCl to regenerate the .aminehydrochlorideand soluble, active streptomycin.

' EXAMPLE 70 1,3-bis-(orthochlorobenzyl)-2-streptmycyl-tetrahydroimidazole sulfate A solution of 3.1 grams ofN,N-bis-(orthochlorobenzyl)-ethylenediamine (dipenicillin G salt meltsabout 133 C.) dissolved in the minimum amount of methanol is added to7.3 g. streptomycin sulfate dissolved in 50 water. The minimum amount ofethanol is added to ensure complete solution. After heating at 45 50 C.for ten minutes, the reaction mixture is allowed to stand at roomtemperature for three days. After cooling, the crystalline product,1,3-bis-(orthochlorobenzyl)-2-strepto mycyl-tetrahydroimidazole sulfate,is filtered off and dried.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

' EXAMPLE 71 I,3 -bisorthohydroxybenzyl -2 -'strept0mycyl-tetruhydroimiduzole sulfate A solution. of 2.7 grams ofN,N'-bis-(orthohydroxybenzyl)-ethylenediamine (dipenicillin G salt meltsabout 115 C.) dissolved in theminimum amount of methanol is added to 7.3g. streptomycin sulfate dissolved in 50 ml.

water. The minimum amount of ethanol is added to ensure completesolution. After heating at 45 -'50 C. for ten minutes, the reactionmixture is allowed to stand at room temperature for three days.Lyophilization of the reaction mixture leaves solid 1,3-bis-(orthohydror:y-

benzyl)-2-streptomycyl-tetrahydroimidazole sulfate.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the 'amine hydrochloride and soluble,active streptomycin.

EXAMPLE 72 l-benzyl-3 (Z-hydroxylbenzyl)-2-strept0mycyltetrahydroimidazole sulfate fate, precipitates as a gumwhich gradually solidifies "upon seeding. V v A 1.5 gram sample of thisimidazole is heated for three hours at 100 C. in 25 ml. of 6N HCl toregenerate the amine hydrochloride and soluble, active streptomycin.

After heating at 45-50 C. for

2.4 EXAMPLE773 lbe nzyl-3-f3 ethoxy-4-hydroxybenzyl)-2-streptomycyl-tetrahydroimidazole sulfate A solution of 3.0 grams of.N-benzyl-N-(3'-ethoxy-4- hydroxybenzyl) ethylenediamine (dipenicillin Gsalt' melts about 120 C.) dissolved in the minimum amount of methanol isadded to 7.3 g. streptomycin sulfate dissolved in 50 ml. Water. Theminimum amount of ethanolis added to ensure complete solution. Afterheating at 45 '50 C. for ten minutes, the reaction mixture is allowed tostand at room temperature for three days.

The precipitate of l benzyl 3 (3 ethoxyl-hydroxybenzyl) 2 streptomycyltetrahydroimidazole sulfate which separates upon the addition of wateris collected by filtration and dried. V

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N I-lCl to regenerate the amine hydrochloride and soluble,active streptomycin.

7 EXAMPLE 744-methyl-1,3-di-n-heptyl-Z-streptomycyl-tetrahydroz'midazole sulfate Asolution of 2.7 grams of l-methyl-N,N'-di-n-heptylethylenediaminedissolved .in the minimum amount of methanol is added to 7.3 g.streptomycin sulfate dissolved EXAMPLE 75 4,5 -dimethyl-1 ,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate A solution of 2.6grams of 1,2-dimethyl-N,N'dibenzylethylenediamine dissolved in theminimum amount of methanol is added to 7.3g. streptomycin sulfatedissolved in 50 ml. water. The minimum amount of ethanol is added toensure complete solution. After heating at 45 50 C. for ten minutes, thereaction mixture is allowed to stand'at room temperature for three days.The product,4,5-dimethyl-l,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate, isrecovered as a solid by lyophi-lization.

A 1.5 gram sample of this imidazole is heated for three hours at C. in25 ml. of 6N HCl to regenerate the V amine hydorchloride and soluble,active streptomycin.

EXAMPLE 76 4-methyl-1,3edibenzyl-2-strept0mycyl-tetrahydroimidazolesulfate A solution of 2.5 grams of l-methyl-N,N'-dibenzylethylenediaminedissolved in the minimum amount of methanol is added to 7.3 gramsstreptomycin sulfate dissolved in 50 ml. water. The minimum amount ofethanol is added to ensure complete solution. After heating at 45 50 C.for ten minutes, the reaction'mixture is allowed to stand at roomtemperature for three days. The product,4-methyl-1,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate,precipitates upon cooling as a somewhat yellow oil which on standingbecomes crystalline. The crystals are removed by filtration and dried invacuo.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

.2 1 EXAMPLE 77 4,5 dimethyl 1,3 di -n heptyl 2-strep-tomycyltetrahydroimidazole sulfate A solution of 2.8 grams of1,2-dimethyl-N,N'-di-nheptylethyl'enediamine dissolved in the amount ofmethanol is added to 7.3 g. streptomycin sulfate dissolved in 50 ml.water. The minimum amount of ethanol is added to ensure completesolution. After heating at -45 50 C. for ten minutes, the reactionmixture is allowed to stand "at room temperature for three days. Theproduct, 4,5 dimethyl 1,3=di n-heptyl 2 streptomycyltetrahydroimidazolesulfate, precipitates upon the addi- "tion of Water and is filtered offand dried.

A 1.5 gram sample of this imidazole is heated for three hours at 100?'C. in 25 ml. of 6N HCl to regenerate the amine hydrochloride soluble,active streptomycin.

EXAMPLE 78 1,5 dimethyl 1,3 dz' cyclohexylr'nethyl 2streptomycyltetrahydroimidazole sulfate A solution of 2.7 grams of4,5-dimethyl-1,3-di-cyclohexylmethyl-2-streptomycyl-tetrahydroimidazolesulfate dissolved in the minimum amount of methanol is added to 7.3 .g.streptomycin sulfate dissolved in 50 ml, water. The minimum amount ofethanol is added to ensure complete solution. After heating at 45-50 C.for ten minutes, the reaction mixture is allowed to stand at roomtemperature for three days. lhe solid product, 4,5 dimethyl 1,3dicyclohexylmethyl 2 streptomycyltetrahydroimidazole sulfate,precipitates upon seeding and the addition of water and is collected byfiltration and dried.

A 1.5 "gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 79 4 a methyl 1,3 di cyclohexylmethyl 2streptomycyltetrahydroimidazole sulfate A solution of 2.6 grams of1-methyl-N,N'-di-cyclohexylmethylethylenediamine dissolved in theminimum amount of methanol is added to 7.3 g. streptomycin sulfatedissolved in 50 ml. water. The minimum amount of ethanol is added toensure complete solution. After heating at 45 --50 C. for ten minutes,the reaction mixture is allowed to stand at room temperature for threedays. Upon cooling and the careful addition of water, the solid'4-methyl-1,3-di-cyclohexylmethyl-2 streptornycyl-tetrahydroimidazolesulfate separates and is collected by filtration. V

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.m 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 80 4,5 dimethyl 1,3 di cyclohexyl 2streptomycyltetrahydroimidazole sulfate A solution of 2.4 grams of'1,2-dimethyl-N,N-di-cyclo- -hexylethylenediamine dissolved in theminimum amount of methanol is added to 7.3 g. streptomycin sulfatedissolved in 50 ml. water. The minimum amount of eth'an01 is added toensure complete solution. After heating at 45 50 C. for ten minutes, thereaction mixture is allowed to stand at room temperature for three days.After cooling, the crystalline product, 4,5-dim'ethyl-l,3-di-cyclohexyl-2-streptomycyl-tetrahydroimidazole sulfate, is filteredoff and dried.

A 1.5 gram sample of this imidazole is heated for three hours at 100 C.in 25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

-. 2 EXAMPLE '81 4 -methyl 1,3 di-cyclohexyl v 2streptomycy'l-tetrahydroimidazole sulfate A solution of 2.3 grams of1-methyl-N, N-di-'cyclohexylethylen'ediamine dissolved in the minim-umamount of methanol is added to 7.3 g. streptomycin sulfate dis solved in50 ml. water. The minimum amount of ethanol is added to ensure completesolution. After heating at 45 50 C. for ten minutes, the reactionmixture is allowed to stand for three days at room temperature.Lyophilization of the reaction mixture leaves solid 4- methyl 1,3 dicyclohexyl 2 streptomycyl-tetrahydroimidazole sulfate.

A 1.5 gram sample of this imidazole is heated for three hours at C. in25 ml. of 6N HCl to regenerate the amine hydrochloride and soluble,active streptomycin.

EXAMPLE 82 1,3-dibenzyl-2streptomycyl-tetrahydroimiclazole sulfate Eightgrams "of solid streptomycin sulfate (potency- 475 u./mgm. by B.subtilis assay; partially purified by adsorption on and elution fromion-exchange resin columns) was dissolved in 50 ml. water and admixedwith a solution of 10 mls. N,N'-di'oenzyl-ethylenediamine in 70 mls.methanol to give a clear solution which was heated to 50 C. for onehour. 1,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate (7.64grams) precipitated and was collected by filtration, dried over P205 andfound to assay 600 units/mgmThe filtrate (78 mls.) assayed 2880units/ml.

7.5 grams of this 1,3-dibenzyl-2-streptomycyl-tetrahydroimida'zolesulfate were placed in water and the pH was adjusted to pH 2 withsulfuric acid. N,N-dibenzylethylenediamine sulfate vprecipitated and wascollected by filtration (1.04 'g.). Addition of five volumes of methanolto the filtrate precipitated solid streptomycin sulfate (4.08 g.)assaying 625 u./mgm.

EXAMTPLE 83 Fifty mls. of streptomycin liquor assaying 182,000 units/ml.(B. subt'lis assay) and obtained by elution of broth adsorbed on anion-exchange resin column was added to 10 mls.N,N'-dibenzylethylenedianrine in 65 'ml-s. methanol, liberating heat andgiving a clear solution which was heated to 50 C. for one hour and thenallowed to stand overnight.l,3-dibenzyl-2-streptomycyltetrahydroimidazole sulfate precipitated andwas collected by filtration, dried over P205 and found to weigh 4.1grams and to assay 528 units/mgm. The filtrate, 39 mls., assayed 2480units/ml.

'F'o'ur grams of this 1,3-dibenzyl-2-streptomycyl-tetra- 'hydroimidazolesulfate was placed in water and the pH was adjusted to pH 2.0 withsulfuric acid. After standing, the volume was reduced by one-half bydistillation in vacuo and the N,N-dibenzyl-ethylenediamine sulfate whichprecipitated (0.92 g. was removed by filtration. The addition of fivevolumes methanol precipitated 2.53 g. streptomycin sulfate assaying 560units/mgm; the filtrate (925 ml.) assayed 122 units/ml.

1,3-dibenzyl-2*streptomycyl-tetrahydroimidazole sulfate (2%) in 4%aqueous acacia suspension has LDsu (minimum lethal dose in 50% ofanimals) of about 3421-21 mgm/kg. by intraperitoneal injection in mice.

7 Streptomycin sulfate,1,3-dibenzyl-2-streptomycyl-tetrahyd'roimidazo'le sulfate and1,3-di(betahenyIethylyZ- 'streptomycl-tetrahydroimidazole sulfate by invitro test all have minimum inhibitory concentrations of 0.0002 mgm/ml.against the streptomycin-sensitive strain H37Rv of Mycobacteriumtuberculosis and all fail to inhibit streptomycin-resistant strainH37RvR.

The CD50 '(Curative Dose-50) is the minimum intraperitoneal dose of thedrug which will cure 50 percent of agrou'p 'of mice injectedintraperitoneally with 100 to 1000 LD50 doses of Dip loco'ccuspneumoniae, each 'liDsb The point of intersection of the probit 5, lineand 'the.

best line constructed through the experimental points describes theconcentration of drug which should protect half the animals under theconditions of the experiment. The antilog of this term is called theCDsu.value. Using aqueous suspensions, including sodium carboxy-.methylecellulose and having pH about 7, of the two new drugs, thefollowing values for CD50 were found as above: 6.8 mgm./kg. forstreptomycin sulfate; 45 mgrn./kg. for1,3-dibenzyl-2-streptomycylterahydroimidazole sulfate; and 60 mgm./kg.for '1,3-di(betaphenethyl)- 2-streptomycyltetrahydroimidazole sulfate.

EXAMPLE 84 1.592 g." of rnicronized1',3-dibenzyl-2-streptomycyltetrahydroimidazole sulfate was thoroughlymixed q. s. ad 20 cc. into peanut oil gelled with 2% aluminummonostearate in the manner of U. S. Patent 2,507,193. The resultingsuspension contained the equivalent of about 50 mgms. streptomycinbase/cc. 7

EXAMPLE 85 3.184 grams of 200 mesh1,3-dibenzyl-2-streptomycyltetrahydroimidazole sulfate was thoroughlymixed q. s.

ad 20 cc. into peanut oil gelled with 2% aluminum monostearate.

7 EXAMPLE 86 3.184 grams of micronizedl,3-dibenzyl-2-streptomyeyltetrahydroimidazole sulfate was thoroughlymixed q. s. ad

' 20 cc. into peanut oil gelled with 2% aluminum monostearate.

EFLAMPLE 87 407.8 g. of 200 mesh1,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate was thoroughlymixed qQs. ad 1100 cc. into peanut oil gelled with 2% aluminummonostearate. Silicone-coated, 15 cc. vials were filled with about 11cc. each of the suspension.

EXAMPLE 88 8.41 g. of 200 mesh1,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate was thoroughlymixed 'q. s. ad 50 cc. into peanut oil gelled with 2% aluminummonostearate. The resulting suspension contained the equivalent of about100 mgms. streptomycin base/ cc.

EXAMPLE 89 2.52 g. of 200 mesh 1,3-dibenzyl-Z-stretomycyI-tetrahydroimidazole sulfate was thoroughly mixed q. s. ad 30vcc. into peanut oil gelled with 2% aluminum 'monostearate. Theresulting suspension contained the equivalent of about 50 mgms.streptomycin base/cc.

EXAMPLE 90 V 168.3 g. of 200 meshl,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate was thoroughlymixed q. s. ad 500 cc. into peanut oil gelled with 2% aluminummonostearate. The resulting suspension contained the equivalent of about200 mgms. streptomycin base/cc. j a

EXAMPLE 91 V I Fifteen grams of 200 mesh1,3-dibenzyl-2-streptomycyltetrahydroimidazole' sulfate wasthoroughly'mixed into 35 cc. of peanut oil gelled with 2% aluminummonos'tea;

rate to give a finished volume of 47 cc... containing the equivalent of0.192 g. streptomycin base/ed. i

dibenzyl 2.-. streptomycyl tetrahydroimidazole sul- EXAMPLEPZ 60 gramsof 200 mesh 1,3 dibenzyl-2-streptomycyltetrahydroimidazole sulftae wasthoroughly mixed into cc. of peanut oil gelled with 2% aluminummonostearate to give a final volume. of 200 cc. containing theequivalent of 185.3 mgm. streptomycin base/cc.

EXAMPLE 93 An aqueous gel was prepared by making'a one'percentsuspension of methylcellulose in propylene glycol, heating themixturewith stirring to C..and continuing the stirringwhile allowingthe mixturetocool to room temperature. T V v 1 3.184 g. of 200 mesh1,3-dibenzyl-Z-streptomycyl tetrahydroimidazole sulfate was thoroughlymixed qs. ad 20 cc. into this gel to give a suspension containing theequivalent of 100 mgms streptomycinbase/cc.

EXAMPLE 94 An aqueous vehicle (called L S T vehicle) containing 0.7%lecithin, 0.33% Span 40, and 0.93% Tween 40fis prepared by addingdistilled water q. s. ad 1000 cc. to lecithin (7.0 g.), Span 40 (3.3 g.)and Tween 40 (9.3 g.), autoclaving, stirring down to room temperatureand add ing water to restore any loss in volume.

Eight silicone-coated, 15 cc. vials were filled with 1.851 g.1,3-dibenzyl-2-streptomycyl-tetrahydroimidazole.

sulfate/vial and reconstituted by the addition of 9.53 cc./ vial of theabove LST vehicle to provide a finished volume of 11 cc. containing theequivalent of 100 mgm. streptomycin base/ cc.

EXAMPLE 95 Eight silicone-coated 15 cc. vials were filled with 0.925 g.1,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate/ vial andreconstituted by the additionof 10.26 cc. of the above LST vehicle toprovide a finished volume of 11 cc. containing the equivalent of 50 mgm.streptomycin base/cc.

EXAMPLE 96 'Ten 15 cc. silicone-coated vials were filled with 1.851

g. l,3 dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate/vialandreconstituted by-the addition of 9.53 fcc.

water to provide a finished volume of 11cc. containing the equiavlent of100 mgm. streptomycin base/cc.

EXAMPLE 97 Ten 15 cc. silicone-coated vials were filled with 0.925 g.1,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate/ vial andreconstituted by the addition of 10.26 cc. water to provide a finishedvolume of 11 cc. containing the equivalent of 100 mgm. streptomycinbase/cc.

EXAMPLE 9s A yial was filled with 0.2388 g. 200 mesh 1,3-dibenzy1-2-s-treptomycyl-tetrahydroimidazole sulfate and 0.0282 g.polyvinylpyrrolidone and reconstituted by the addition of 2.8 cc. waterto give a final volume of 3 cc. containing the equivalent of 50 mgm.streptomycin base/ cc.

7 EXAMPLE 99 V Eighteen grams of 200 mesh1,3-dibenzyl-2-streptomycyltetrahydroimidazole sulfate were suspended in50 cc.

of a 0.7% aqeous solution of Tween 40 to give a final volume of 63.5 cc.containing the equivalent of mgm.

streptomycin base/cc. a

EXAMPLE 10,0 r Twenty-cc..via1s were filled with 3 g. of 200 mesh 1,3

fate/vialand reconstituted with 7 cc./vial of a 0.7 aqueous solution of.Tween 40 to give a final volume of 9.25 cc. containing the equivalent of203.5 mgm. streptomycin base/cc.

hours in a mixer.

29 EXAMPLE 101 300 g. micro-pulverized=1,3-dibenzyl-2-streptomycyltetrahydroimidazole sulfate and 35 cc.chloroform containing 3:99 g. lecithin, 1.88 g. Span 40, and 5.30 g.Tween 40 were placed in a mixer with thirty-five steel balls and mixedfor seven 'hours. The chloroformwas then driven off by a current of airat room temperature. The coated 1,3-dibenZylZ-streptomycyltetrahydroimidazole sulfate was .passed through a 250 meshscreen and then sterilized with a gaseous formaldehyde for fortySilicone-coated 20 cc. vials were filled with about 3.492 g. (3.31 to3.66 g.) of this material. There was 37.2 mgms. of coating per gram of1,3-dibenzyl-2-streptomycyl-tetrahdroimidazole sulfate. Reconstitutionby addition of about 7.22 cc. water gave a final volume of .cc. of asuspension containing the equivalent of 200 rngm. streptomycin base/ cc.

EXAMPLE 102 A vial was filled with 0.2388 g. 200 mesh1,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate, 0.0282 g. 60mesh dextran and reconstituted by the addition of 2.8 cc.'water to givea final volume of 3 cc. containing the equivalent of 50 mgm.streptomycin'base/cc.

EXAMPLE 103 Streptomycin sulfate (491 g., 0.675 mole) was dissolved withstirring in 1675 ml. water, filtered and the filtrate combined with 200ml. water used to wash the N,N'-dibenzylethylenediaminediacetate (487g., 1.35 moles) was suspended in 1000 ml. of water and neutralizedwith50% aqueous sodium hydroxide. After standing, the lower aqueous layerwas separated and discarded. The pale ellow, liquid amine was washedwith water (500 ml.), separated from the wash water, dissolved inone'liter methanol and added to the aqueous 'sol'uti'on'of CalculatedFound 7 0.- 47. 3 47.2 H 6. 77 6. 73 S 3.42 3.29;-3.44 H 3. 84

loss of water at 80 C. over P205, '3.14; pick-'up of water of anhydroussalt, 4.05, 4.15; residue 0.8%.

The pH of a saturated aqueous solution at room temperature of this1,3-dibenzyl-2streptomycyl-tetrahydroimidazole sulfate was 8.8.

EXAMPLE 104 N,N'-dibenzylethylenediamine diacetate (1683 g., 4.67 males)was suspended in 3330 ml. of water and with vigorous mechanical stirringneutralized to pH 10-11 with about 500-525 ml. 50% aqueous soldiumhydroxide. The liberated base was separated, washed with -1.5 1. ofwater, dissolved in 6650 ml. of methanol and this solution was addedrapidly to a mechanically stirred, filtered solution of streptomycinsulfate (1637 g.; 2.25

' moles; potency 718 u./mgm. by maltol and 651 u./mgm.

by bio-assay; 2.5% streptomycin B by activity; 9.3%

'30 streptomycin B by weight; 6.55% moisture content) in 5585 .1111. ofwater. After heating to about 350 "C. in the =cou1se of about-'35minutes, the mixture was cooled :to =6 "C. :and the precipitated 1,3'-dibenzyl-2-streptomycyltetrahydroimidazole sulfate was collected byfiltration, washed with 455 1. chilled-methanol, air-dried and combinedwith the ,product obtained from two other essentially duplicate runs;total weight 4849 g. The average potency of the product was 594 u./mgm.by bio assay and 599 u./mgm. 'by maltol. The product melted about245-250 C. (browns at 180 C., sinters around 240 C.) The productcontained 1.3% streptomycin B by activity and 5% by weight. The productcontained 031% residue and 3.78% moisture. The .pH of a saturatedaqueous suspension of theuproductat room temperature was 8.9. A samplewas dried at in vacuo over P205.

Analysis: Calculated for C3-zHa'zNs011-H2SO4:

3 Calculated I Found CONTROL EXAMPLE 1 An aqueousgel'was "prepared bymaking a one percent suspension of methylcellulose'inpropylene glycol,heating the mixture with stirring to 150 C. and continuing the stirringwhile allowing the mixture to cool to room tem- 2744 g. of 200 meshstreptomycin sulfate was thoroughly mixedq. s. ad 20 cc. into thisgel'to give a suspension containing the equivalent of m'gms.streptomyc'in base/c'c.

CONTROL 2 2.744. grams of200'mesh streptomycin sul-fate was thoroughlymixed .q. s. ad 20cc. into peanut oil gelled with 2%-al-uminum'monostearate to give a suspension containing the equivalentof '100mgm. streptomycin base/ cc.

CONTROL EXAMPLE 3 CONTROL EXAMPLE 4 55.8 grams 200 mesh streptomycinsulfate (728 'u./mgm.) was made up to 200 cc. with a 0.7% aqueoussolution of Tween 40 to give a solution containing the equivalent of203.5 rngm. streptomycin base/cc.

CONTROL EXAMPLE 5 7.14 grams of finely-divided streptomycin sulfate wasthoroughly mixed q. s. ad 50 cc. into peanut oil gelled with 2% aluminummonostearate to give a suspension containing the equivalent 'of 100mgms. streptomycin base/cc.

CONTROL EXAMPLE 6 2.14 grams of finely-divided streptomycin sulfate wasthoroughly mixed q. s. ad 30 cc. into peanut oil gelled with 2% aluminum'nionostea'rate to give a suspension containing the aqui-valent of 50rngm. streptomycin base/cc.

31 V 32 ..CONTROL EXAMPLE7 b is H Mi e um e lllVlVlIl 7.14 grams ofstreptomycin sulfate was dissolved N b {E I D bin U W h eu Chall g datig iv q. s. ad 50 co. in the above LST vehicle to give a solu- V um 8rgg% f gg fi g tion containing the equlvalent of 100 mgm. streptomycin Vg base/cc. V fihrs. 24 hrs. 48hrs.

7 CONTROL EXAMPLE 8 2.14 g; streptomycin sulfate was dissolved'q. 8. adgi l $323 g g 30 cc. in the above LST vehicle to give a solution con-Control Exaiibi'i I II 1 4 1' 1 1 taining the equivalent of 50 mgrns.streptomycin base/cc. 10 1 v CONTROL/EXAMPLE 9 v The iigures inparentheses represent the number'of u a mice dying before challenge,that 1s, death knownto'be Finely-divided streptomyc n V sulfate wasthoroughly due to drug toxicity. q 7 mixed into 140 cc. of peanut oilgelled with 2% aluminum monostear-ate togive a suspension containing theequiv- COMPARISON EXAMPLE NO. 4 V alent of 18.53 stll'eptomyclrn T Theproducts of Exaruples 88 and 89 and of Control j COMPARISON EXAMPLE NO.1 7 Examples 5 aud o were injected intramuscularly in single doses (0.2ml. "or 0.1 ml.) containing the equivalent of The products of Example100 and Control Example 4 were injected intramuscularly in singledoses'containing 5 500 '9 gg fi figfgg g g i sj g 32 5 22 2; theequivalent of 203 mgm. streptomycin base/kgm. in 5 3 g 48 a 72 ai before2 6 infra five mice lthre? challenge immf' erito'heall w'tl1 ISOLD dosesof Di l cocci! 7 neu- Peritoneany with 100 LDED doses of Diplococc'uspneu' Enoniae 'l he tables helovir ive the resul ts X re r sents moniae'All of meet-niece: injre'ctfidjw-iththeeplrqdqgt' of i an animal d dafter infectisnre rese nts an animal Example 100(13dibenzyla-streptomycyl-tetrahydrm 25 d ad before ifec-tion (dru'tcixi tyy a blank means all imidazole Sulfate in Water and Tween 40)survived; none tcfn mice sun li ed" a lar e filia onal cross means thatthe of the mice injected with the product of Control Example ex erimentg 6, Tun i an or most of the animals 4 (streptomycin sulfate in waterand Tween 40) survived. w 5 1d die of dni tbxicit at that dose 7 g Thisindicates thatthe former product exerts repository 7 g y t' th ltt do t.V :7 V 7 ac 10m and e a er es no1,3-dibenzyl-2-streptomycyl-tetrahydrolmidazole sulfate COMPARISONEXAMPLE NO. 2 in peanut oil gelled with. 2% aluminum mona- The productsof Example 92 and Control Exa mple 9' Steam 7 I wereinjectedintramuscularly in single doses containing the equivalent of 926 mgm./kg. in groups of five mice Do-Se 9 Drug and Challengar each atperiods twelve hours, twenty-four hours, and mgmJkg. 7 forty-eight hoursrespectively before challenge intra- 48 24 12 6 3 peritoneally with 100LDso doses of Diplococcus pneumoniae. All the mice injected with theproduct of Ex- X Y i ample 92(1,3dibenzyl-2-streptomycyl-tetrahydroimid- I 7 azole sulfate in peanutoil gelled with 2% aluminum 50D XX X ,monostearate) survived. Two out ofeach five mice inp I I jected with the product of Control Example 9(strepto- 250 X X X mycinr sulfate in peanut oil gelled with 2% aluminum1 v XXXXX XXXXX XXXXX X monostearate) died before challenge due to thetoxicity 49 p 7 I p Streptomycin sulfate in; peanut oil gelled with 2%aluminum monostaqrate D Hours Between Drug and Ohalleuge 088, v r 72 4s24 i2 6 3' 1.5

1,ooo xxxx xxxxx V XXXX XXXX XXXXX 50o xxxxx xxxx xxxxxjx'xj, j;,,1..jifI XXXX XXXXX xxxxxxm 250- xxxx. XXxXx- XXXXXQ V XXXX' 7 XXXXX XXXXXXXXXX XXXXX XXXXX XXX' 78) V of this drug; either two orthree of theremaining three mice in each group failed to survive the challenge. Theuse of a non-toxic dose of the product of Control Example 9 (185mgm./kg.) failed to protect more than one action than the productcontaining streptomycin sulfate.

7 COMPARISON EXAMPLE NO. 3

1 An experiment similar to that above using a dosage of 1000 'mgm/k'g.gave the following tabulatedrest lis 911 N groups of five'mi'ce. 7

'The superior repository action of the formulations of1,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate over thoseofstreptomycin sulfate is apparent at all three doses (0.2 ml.'or 0.1 ml.)containing the equivalent of 250, 500 or 1000 mgmxstreptomycin base/kg.into groups of ten mice .each' at intervals'in similar experiments of1.5, 3, 6, .1 2, and 24 hours before challenge intraperitoneally with1.1350 doses of Diplo coccus pneup moniae. The tables below give theresults; X represents '33 an animal dead after infection; represents ananimal dead before infection (drug toxicity); a blank means all ten micesurvived; a large diagonal cross means that the experiment was not runbecause all or most of the animals would die of drug toxicity at thatdose.

1,3-dibenzyl-2-streptomycyl-tetmhydroimidazole sulfate in aqueouslecithin, Span 40 and Tween 40 Hours Between Drug and Challenge Dose,mgmJ p 1,000.-. X XXX 500 XXXXX XXXXX XX XXXX XXXXX 250 XXXXX XXXXX XXXXXX XXXXX XXXXX XXXXX @XXXX Streptomycin sulfate in aqueous lecithin,Span 40 and Tween 40 Hours Between Drug and Challenge Dose,

mgm./ kg.

XXXX XXXXX XXXXX XXXXX XXXXX XXXXX 250.-. XXXX XXXXX XXXXX XXXXX Thesuperior repository protective action and the reduced toxicity of .the1,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate formulationscompared to those of streptomycin sulfate is apparent at both lowerdosage levels.

COMPARISON EXAMPLE NO. 6

The products of Examples 96 and 97 and solutions of streptomycin sulfatein water were injected intramuscularly in single doses (0.2 ml. or 0.1ml.) containing the equivalent of 250, 500 or 1000 mgm. streptomycinbase/ kg. into groups of ten mice each at intervals in similarexperiments of 1.5, 3, 6, 12, and 24 hours before challengeintra-peritoneally with 100 LDso doses of Diplococcus pneumoniae. Thetables below give the results; X represents an animal dead afterinfection; represents an animal dead before infection (drug toxicity); ablank means all ten mice survived; a large diagonal cross means that theexperiment was not run because all or most of the animals would die ofdrug toxicity at that dose.

The superior repository protective action and the re duced toxicity inwater of .1,3-dibenzyl-2-streptomycy1- tetrahydroimidazole sulfate ascompared to streptomycin snlfateis apparent at both lower dosage levels.

This application is a continuation-in-part of my prior co-pendingapplication of Serial Number 338,129, filed February 20, 1953.

I claim:

1. A compound selected from the group consisting of compounds having theformula CH S treptomycyl wherein R1 and R2 represent radicals selectedfrom the group consisting of alkyl, cyclopentyl, cyclopentyl-loweralkyl, cyclohexyl, cyclohexyl-lower alkyl, lower alkyl-cyclohexyl-loweralkyl, lower alkoxy-cyclohexyl-lower alkyl, lower alkyl-cyclohexyl,lower alkoxy-cyclohexyl, dehydroabietyl, pyridyl, lower alkyl-pyridyl,thiophene-lower alkyl, lower alkyl-thiophene-lower alkyl, furan-loweralkyl, lower alkyl-furan-lower alkyl, quinolyl-lower alkyl, naphthyl,benzhydryl, piperonyl, thiazolyl, phenyl, lower alkyl-phenyl-loweralkyl, phenyl-lower alkyl, halophenyllower alkyl, nitrophenyl-loweralkyl, hydroxyphenyl-lower alkyl, HzN-phenyl-lower alkyl, loweralkoxy-phenyl-lower alkyl, alkoxy-hydroxy-phenyl-lower alkyl, anddi-lower alkyl-monohydroxy-phenyl-lower alkyl; R3 and R4 are membersselected from the group consisting of hydrogen and methyl; and

(b) acid addition salts thereof.

2. Acid addition salts of1,3-dibenzyl-2-streptomycyltetrahydroimidazole.

3. Acid addition salts of1,3-di(B-phenethyl)-2-streptomycyl-tetrahydroimidazole.

4. Acid addition salts of 1,3-di(dehydroabietyl)-2-streptomycyl-tetrahydroimidazole.

5. Acid addition salts of 1,3-di-(l,1,3,3-tetrarnethyl-nbutyl)-2-streptomycyl-tetrahydroimidazole.

6. Acid addition salts of1,3-dicyclohexyl-2-streptomycyl-tetrahydroimidazole.

7. 1,3-dibenzyl-2-streptomycyl-tetrahydroimidazole sulfate.

8. 1,3 dim phenethyl) 2 streptomycyl tetrahydroimidazole sulfate.

9. 1,3 di(dehydroabietyl) 2 streptomycyl tetrahydroimidazole sulfate.

10. 1,3 di (1,1,3,3 tetramethyl n butyl) 2-streptomycyl-tetrahydroimidazole sulfate.

11. 1,3 dicyclohexyl 2 streptomycyl tetrahydroimidazole sulfate.

12. A therapeutic composition comprising a liquid sus- V 35, V pendingmedium, a finely-divided solidse lected from the group consisting ofcompounds having the formula V 2 du -A m V R I I l-11:

treptomycyl wherein R1 and R2 represent radicals selected from the groupconsisting of alkyl, cyclopentyl, cyclopentyl-lower alkyl, cyclohexyl,cyclohexyl-lower alkyl, lower alkylcyclohexyl-lower alkyl, loweralkoxy-cyclohexyl-lower alkyljR and R4 are membersselectedfromthe groupconsisting of hydrogen and methyl; and

(b) acid addition salts thereof, and a suspending'agent for suspendingsaid solid in said liquid medium.

13. A therapeutic composition comprising a liquid suspending medium, afinely-divided, solid, nontoxic acid addition salt of1,3-dibenzyl-Z-streptomycyl-tetrahydroimidazole, and a suspending agentfor suspending sai solid in said liquid medium.

14. A therapeutic composition comprising a liquid suspending medium,finely-divided solid 1,3-dibenzyl-2-strep tomycyl-tetrahydroimidazolesulfate, and a suspending agent for suspending said solid in said liquidmedium References Cited in the file of this patent UNITED STATES PATENTS2,607,770 Winsten Aug. 19, 1952

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF COMPOUNDS HAVING THEFORMULA